{"status":404,"status_message":"Numeric ID required","data":false} {"status":200,"status_message":"Picture qCXikKusLa","data":{"picture_id":"2264","moddate":"2018-12-20 16:09:26","title":"How much feldspar to using in a Grolleg porcelain","alttag":"","titletag":"","metadescrip":"","metakeys":"","S3URL":"https:\/\/reference.s3.us-west-2.amazonaws.com\/images\/pictures\/9fykyfigjc.jpg","S3Date":"2018-11-26 14:29:05","picture_date":"2018-11-26 14:28:29","path":"images\/pictures\/","filename":"9fykyfigjc.jpg","deleted":"0","notfound":"0","descrip":"These are porcelains are made using Grolleg kaolin. P700 (Plainsman) has 19% G200 Feldspar and Coleman (popular among potters in the US) has 31% (P700 switches the 12% to kaolin). Although the Coleman porcelain is more vitreous (top right) it is not more translucent. But it is a lot more problematic in fired warping and plucking (lower left). Grolleg kaolin has a high natural flux content so less feldspar is needed than in recipes calling for American kaolins. And that extra kaolin in P700 gives us something: More plasticity. Another thing: These are not as translucent as what can be achieved at middle temperature oxidation.","disqualify":"0","timelinephoto":"1","timeline_name":"","plainsman":"","insight_help_id":"0","links":{"material":[{"link":"material\/Grolleg+Kaolin","label":"Grolleg Kaolin","ord":"0"}]},"pictures":{"2263":{"z":"SYsfqr5eso","alttag":"A slab-built porcelain mug with yellow glaze showing off its translucency in sunlight","titletag":"The lab-built porcelain mug really shows off its translucency in sunlight!","title":"The translucency of Polar Ice porcelain","notes":"Polar Ice is made by Plainsman Clays, it is by far the most expensive body they make (because of the use of New Zealand kaolin and VeeGum). I call these my \"sunshine mugs\". They are fired at cone 6 (2200F) with a transparent glaze on the inside (G2926B) and G2934Y yellow silky matte on the outside. This yellow glaze showcases the translucency in sunlight better than any other I have seen. The high plasticity and this \"pie crust\" method of making them enables thinner walls than any other method I know of, even casting. Although the walls of this piece are about 3.5 mm thick, I have achieved 2 mm using stiffer clay! Even with very thin walls the weight of the handle does not pull the lips of these into an oval-shape.","filename":"3wstw78bwa.jpg","path":"images\/pictures\/","picture_date":"2018-11-26 14:14:50","S3URL":"https:\/\/reference.s3.us-west-2.amazonaws.com\/images\/pictures\/3wstw78bwa.jpg","S3Date":"2018-11-26 14:15:01","timelinephoto":"0","ord":"0"}}}}